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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

96
ALASKAN GLACIER STUDIES
thinner. This retreat is also shown by comparing 1906 and 1909 photographs from Gilbert's 1000 foot station above Osier Island. Exactly the opposite condition was observed in the tidal portion of the glacier, for in 1909 the point of the ice cliff projected so far as to hide the western margin of Hubbard Glacier which was visible from this photographic site in 1905, indicating an advance of several hundred yards. In 1906 the black point of Haenke Glacier was visible from one of our photographic sites on the south side of Turner Glacier, but in 1909 it had disappeared. This, however, is due in part to the recession of Haenke Glacier.
Condition in 1910 and, 1913. There was no great change in Turner Glacier from 1909 to 1910. From Osier Island (Photo sta. C, Map 8) neither the north nor south edges showed any change (PI. XL, A) but from Gilbert's photographic site 1000 feet above Osier Island (Station D, Map 3) it was apparent in 1910 that there had been a very slight retreat of the south edge and possibly of the north edge also. Prom both stations an increase of the area of dirty ice on the north margin was apparent. From the crest of Haenke Island (Photo, station A, Map 8), which was not visited in 1909, it was clear that there had been some retreat of the south edge between 1906 and 1910 and, with the recession of Haenke Glacier, of the north edge also. No change in the middle portion was apparent. In September, 1918, when the junior author visited Yakutat Bay with the International Geological Congress, the Turner Glacier was seen to have continued its retreat. The tips of both the north and south wings of the glacier, especially the latter, were so inactive that they had ceased to discharge icebergs. They were covered with ablation moraine to a greater extent than at any time in the previous eight years. Very few icebergs were being discharged from the middle of the glacier cliff. It is clear, therefore, that the relative inactivity of Turner Glacier was continued at least until September, 1918.
TURNER GLACTZB
Year	Nature of Change		Based on observations by
1890-1891		Retreat /	Russell
1891-1895	Retreat		Boundary Survey
1895-1897	Retreat		Bryant
1891-1899			Gilbert
1899-1901	Advance middle and beginning in edges		Fish Commission
1901-1905	Advance north and treat middle	south edges, re-	Tarr and Martin
1905-1906	Advance of middle, and south edges	retreat of north	Tarr
1906-1909	Retreat of north and south edges		Tarr and Martin
1909-1910	Retreat		Martin
1910-1918	Retreat, especially at south edge		Martin